5 files changed, 59 insertions, 6 deletions

diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index 3a23dbd0d2..6c178c31d4 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -26,6 +26,7 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON_NHLT
 	# Misc options
 	select C_ENVIRONMENT_BOOTBLOCK
+	select CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM if RELOCATABLE_RAMSTAGE
 	select COLLECT_TIMESTAMPS
 	select COMMON_FADT
 	select GENERIC_GPIO_LIB
@@ -34,7 +35,6 @@ config CPU_SPECIFIC_OPTIONS
 	select MMCONF_SUPPORT
 	select MMCONF_SUPPORT_DEFAULT
 	select NO_FIXED_XIP_ROM_SIZE
-	select NO_STAGE_CACHE
 	select NO_XIP_EARLY_STAGES
 	select PARALLEL_MP
 	select PCIEXP_ASPM
@@ -254,4 +254,8 @@ config SPI_FLASH_INCLUDE_ALL_DRIVERS
 	bool
 	default n
 
+config SMM_RESERVED_SIZE
+	hex
+	default 0x100000
+
 endif
diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c
index f3cf050415..e67842c369 100644
--- a/src/soc/intel/apollolake/cpu.c
+++ b/src/soc/intel/apollolake/cpu.c
@@ -102,19 +102,23 @@ static void get_smm_info(uintptr_t *perm_smbase, size_t *perm_smsize,
 {
 	void *smm_base;
 	size_t smm_size;
+	void *handler_base;
+	size_t handler_size;
 
 	/* All range registers are aligned to 4KiB */
 	const uint32_t rmask = ~((1 << 12) - 1);
 
 	/* Initialize global tracking state. */
 	smm_region(&smm_base, &smm_size);
+	smm_subregion(SMM_SUBREGION_HANDLER, &handler_base, &handler_size);
+
 	relo_attrs.smbase = (uint32_t)smm_base;
 	relo_attrs.smrr_base = relo_attrs.smbase | MTRR_TYPE_WRBACK;
 	relo_attrs.smrr_mask = ~(smm_size - 1) & rmask;
 	relo_attrs.smrr_mask |= MTRR_PHYS_MASK_VALID;
 
-	*perm_smbase = relo_attrs.smbase;
-	*perm_smsize = smm_size - CONFIG_SMM_RESERVED_SIZE;
+	*perm_smbase = (uintptr_t)handler_base;
+	*perm_smsize = handler_size;
 	*smm_save_state_size = sizeof(em64t100_smm_state_save_area_t);
 }
 
diff --git a/src/soc/intel/apollolake/include/soc/smm.h b/src/soc/intel/apollolake/include/soc/smm.h
index 7a9846eea2..740d02b114 100644
--- a/src/soc/intel/apollolake/include/soc/smm.h
+++ b/src/soc/intel/apollolake/include/soc/smm.h
@@ -20,6 +20,7 @@
 
 #include <stdint.h>
 #include <soc/gpio.h>
+#include <fsp/memmap.h>
 
 /* These helpers are for performing SMM relocation. */
 void southbridge_clear_smi_status(void);
@@ -35,7 +36,4 @@ void southbridge_smm_enable_smi(void);
 /* Mainboard handler for GPI SMIs*/
 void mainboard_smi_gpi_handler(const struct gpi_status *sts);
 
-/* Fills in the arguments for the entire SMM region covered by chipset
- * protections. e.g. TSEG. */
-void smm_region(void **start, size_t *size);
 #endif
diff --git a/src/soc/intel/apollolake/memmap.c b/src/soc/intel/apollolake/memmap.c
index ea6f447d43..cccbffd40d 100644
--- a/src/soc/intel/apollolake/memmap.c
+++ b/src/soc/intel/apollolake/memmap.c
@@ -24,6 +24,7 @@
 #define __SIMPLE_DEVICE__
 
 #include <arch/io.h>
+#include <assert.h>
 #include <cbmem.h>
 #include <device/pci.h>
 #include <soc/northbridge.h>
@@ -52,3 +53,34 @@ void smm_region(void **start, size_t *size)
 	*start = (void *)smm_region_start();
 	*size = smm_region_size();
 }
+
+int smm_subregion(int sub, void **start, size_t *size)
+{
+	uintptr_t sub_base;
+	size_t sub_size;
+	const size_t cache_size = CONFIG_SMM_RESERVED_SIZE;
+
+	sub_base = smm_region_start();
+	sub_size = smm_region_size();
+
+	assert(sub_size > CONFIG_SMM_RESERVED_SIZE);
+
+	switch (sub) {
+	case SMM_SUBREGION_HANDLER:
+		/* Handler starts at the base of TSEG. */
+		sub_size -= cache_size;
+		break;
+	case SMM_SUBREGION_CACHE:
+		/* External cache is in the middle of TSEG. */
+		sub_base += sub_size - cache_size;
+		sub_size = cache_size;
+		break;
+	default:
+		return -1;
+	}
+
+	*start = (void *)sub_base;
+	*size = sub_size;
+
+	return 0;
+}
diff --git a/src/soc/intel/apollolake/romstage.c b/src/soc/intel/apollolake/romstage.c
index b9733defa3..2384ceb1cf 100644
--- a/src/soc/intel/apollolake/romstage.c
+++ b/src/soc/intel/apollolake/romstage.c
@@ -29,6 +29,7 @@
 #include <device/pci_def.h>
 #include <device/resource.h>
 #include <fsp/api.h>
+#include <fsp/memmap.h>
 #include <fsp/util.h>
 #include <soc/iomap.h>
 #include <soc/northbridge.h>
@@ -105,6 +106,9 @@ asmlinkage void car_stage_entry(void)
 	uintptr_t top_of_ram;
 	bool s3wake;
 	struct chipset_power_state *ps = car_get_var_ptr(&power_state);
+	void *smm_base;
+	size_t smm_size;
+	uintptr_t tseg_base;
 
 	timestamp_add_now(TS_START_ROMSTAGE);
 
@@ -135,6 +139,17 @@ asmlinkage void car_stage_entry(void)
 		postcar_frame_add_mtrr(&pcf, -CONFIG_ROM_SIZE, CONFIG_ROM_SIZE,
 					MTRR_TYPE_WRPROT);
 
+	/*
+	* Cache the TSEG region at the top of ram. This region is
+	* not restricted to SMM mode until SMM has been relocated.
+	* By setting the region to cacheable it provides faster access
+	* when relocating the SMM handler as well as using the TSEG
+	* region for other purposes.
+	*/
+	smm_region(&smm_base, &smm_size);
+	tseg_base = (uintptr_t)smm_base;
+	postcar_frame_add_mtrr(&pcf, tseg_base, smm_size, MTRR_TYPE_WRBACK);
+
 	run_postcar_phase(&pcf);
 }